Samuel L. Jackson set for "The Secret Service"

"The Avengers: Age of Ultron" is the sequel to the blockbuster hit of 2012, “The Avengers”. Iron Man, Thor, Captain America, and The Hulk are all scheduled to return as well as well as a few new characters, like Quicksilver, and The Falcon.

'The Avengers' actor has landed a leading role opposite Colin Firth in Matthew Vaughn's latest comic book adaptation, which is based on Mark Millar and David Gibbons' super-spy graphic novel series, according to Variety.

Jackson will play the main antagonist to Firth's expert secret agent and his young rookie protégé, to be played by newcomer Taron Egerton.

Vaughn - who previously directed another Millar comic book adaptation, 'Kick-Ass', as well as 'X-Men: First Class' - has been eyeing a big Hollywood name for the role, and previously offered the part to Tom Cruise and Leonardo DiCaprio.

The plot centres on a British spy who takes a brash young upstart under his wing and teaches him the tricks of the trade.

Vaughn co-wrote the script with his regular collaborator Jane Goldman - who co-wrote 'Stardust' and 'Kick-Ass' with him - and he will produce as well as direct through his Marv Films production company.

Attention now turns to finding the film's leading lady and it's thought producers are keen on 'The Bling Ring' and 'Harry Potter' star Emma Watson, but are also considering 'Dark Shadows' actress Bella Heathcote.

Jackson is currently filming Marvel comic book movie, 'Captain America: The Winter Soldier', reprising his role as S.H.I.E.L.D. leader Nick Fury. He will again play the role in 'The Avengers: Age of Ultron', which will be filmed next year for release in 2015.

'The Secret Service' is due to begin production later this year and will be released in November 2014.